Device for adjusting inner rolls in rolling mills for rolling pipes



1942- M. ROECKNER 2,305,794

DEVICE FOR ADJUSTING INNER ROLLS IN ROLLING MILLS FOR ROLLING PIPES Filed March 22, 1940 2 Sheets-Sheet 1 w wwgy Dec. 22, 1942. M. ROECKNER 2,305,794 DEVICE FOR ADJUSTING INNER ROLLS 1N ROLLING MILLS FOR ROLLING PIPES Filed March 22, 1940 2 Sheets-Sheet 2 X\ Ely-3a this to such a high degree,

excellent rolling method becomes thereby un- Patented Dec. 22, 1942 DEVICE FOR.

ROLLING ADJUSTING-INNER ROLLS IN MILLS FOR ROLLING Martin Itoeckner, Mulheim, Ruhr, Germany;

vested in the Alien Property Custodian Application March 22, 1940, Serial No. 325,451

In Germany March 23, 1939 I Claims. ((21. 80-13) Rolling methods for the production of seamless pipes are known, and especially for rolling pipes of large diameter, in which outer grooved rolls coacting with the exterior of the pipe are used in conjunction with inner rolls arranged on a mandrel head held by a rod-shaped mandrel.

In order to obtain, during. the to-and-fro movement by such rolling methods, alteration of shape of the material to be rolled, the outer rolls are arranged so that they can radially approach the material to be rolled and be moved away from the same. It has also been proposed to arrange the inner rolls so that they can approach the material to be rolled and be moved away from the same. with this object in view it has been proposed to omit the mandrel head proper in the device for carrying out one of the well known methods and to mount the housing for the inner rolls in a leverage, which can be adjusted by screw spindles so that the rolls can be moved towards and away from the material to be rolled.

Such adjusting devices for inner rolls in rolling mills for hollow bodies have been employed as a rule when only one or two rolls are required to act in the interior of the hollow ingot.

Other known rolling methods attain an adjustability of the inner rolls in radial direction by placing the bearing bodies on a wedge. The bearing bodies were then guided in the mandrel head itself and could be moved by movement of the wedge in radial direction away from or towards the material to be rolled.

As a mechanical adjustability of the inner rolls could not be obtained up to the present without reducing the strength of the mandrel head, me

chanical adjustability of the inner rolls had' to be dispensed with in rolling mills destined for carrying out the above mentioned known methods. By removing the inner roll and by using supports for its bearing bodies it was possible to adjust the inner roll by hand during the intervals between the rolling. This method, how ever, involves loss of time and the unavoidable keeping warm of the material to be rolled, and that'this otherwise economical- I This invention has ior'its object to provide a durable and practical device for facilitating swift and convenient adjustment of the inner rolls of the rolling In the accompanying drawings s Fig. 1 illustrates how the known method is carried out without adjusting of the irmer rolls,

Fig. 2'shows 115w the adjusting of the inner 'rolls affects the-operation of the rolling mill,

Fig. 3 is a fragmentary detail in sectionofa mandrel showing the invention applied thereto,

Fig. 3a is a view similar to Fig. 3 showing a different adjustment of one of the inner rolls,

Fig. 4 is a detail plan view of Fig. 3 with parts removed, I Y v Fig. 5 is a sectional view taken at right angles to Fig, 3,

Fig. 6 is a view similar to Fig. 4 in which the mandrel head is shown in section,

Fig. '7 is a view similar to Fig. 5 showing the parts in a different position,

Fig, 8 is a detail section similar to Fig. 3 showing a modification of theinvention.

In Fig. 1, A designates the outer rolls of the rolling mill, B the inner rolls, E the mandrel head and D the bearing bodies in which the rolls B are mounted in E. The material to be rolled is designated by C.

From Fig. 1 can be seen how the material C to be rolled, shown in full lines, changes its shape under the action of the rolls A and B so that the neutral fibre of the wall is approximately preserved. The material to be rolled, undergoes a change in shape as indicated in full lines in Fig. 1, under the action of the left hand passes of the outer and inner rolls A and B, when the material is moved to'the right. Before passing the materialzto the left, the outer rolls A. are moved inwardly a. distance and oscillated thereby first efiecting a reduction of the mean diameter Z of the material. During the passing of the material to the left. the right hand passes of the rolls A andBeflect a reduction of the thickness and an increase in the length of the material as indicated in dot and dash lines in Fig. 1.

According to Fig. 2, after the first pass of the material to the right, the inner rolls B are moved closer to the material to the extent of the pass depth and, =moreover the outer rolls are oscillated and also moved closer to the material whereupon the pass of the material to the left is eiiected without a reduction'of the mean diameter Z of the material to be rolled as required according to Fig. 1. The total efliciency available for the alteration of the shape of the material to' be rolled can thereby be fully utilized for the intended alteration of the shape, which is the reduction oi? the wall thickness and the stretching of the material to be rolled.

Referring in detail to Figs. 3 to 8 B designates an inner roll, E the mandrel head and D a bearing body of the inner roll B. The shaft of 'roll B is extended on both ends beyond the bearing. Only the arrangement of one shaft end is shown. This extension can be made in one piece with the shaft, but it might be produced by screwing in or shrinking of a piece of corresponding length. The extended end of the roll shaft extends through the opening in the head of a press piston H. If, after the material to be rolled has passed once through the rolling mill the roll B has to be adjusted in radial direction to the material, the press piston H is lifted by introducing a pressure medium into the bottom of the cylinder until the piston movement is stopped by a device I. In a pocket like indentation X in the mandrel head E several supporting plates F for the bearing body D are accommodated, one plate being disposed on the other. This sprocket like indentation in the mandrel head E serves merely as a recess to accommodate the supporting plates F. .This space is closed at the upper end by a lid Q (Fig. 3a), so that a chamber is formed which is closed on all sides except for a slot like aperture b of such dimension that actually one supporting plate F can be pushed out of the chamber through this slot. The upper surface of the supporting plate on top is pressed against the lower side of the lid Q of the storage chamber by the pressure exerted by springs G. The slot b is covered by the bearing body D but when the roll B together with the bearing body are lifted bythe piston H, the slot is uncovered. The press piston K is then actuated and shifts, by means of a device L mounted on its head, one of the supporting plates F so that this plate is introduced intothe gap between the bearing body D and the mandrel head E produced by the lifting of roll, 13 together with the bearing body D. If the pressure, which acts upon the press pistons H and K is relieved, the supporting plate F remains in its position between bearing body D and mandrel head E and the roll B has been adjusted. The pressure springs G are arranged under the supporting plates F and, after insertion of the first supporting plate, lift the other plates so that at the next following lifting movements of piston H the plates can be suc-' cessivelypushed into the free space under the bearing body D. In order that the previously inserted Supporting plate F will be lifted together with the bearing body D, the supporting plates F as well'as the bearing body D are equipped, as can be seen from Fig. 3, with interengaging dovetail rib and groove a. To ensure that at each actuation of the press piston H the roll 13 is lifted only so much that the supporting plate can be pushed in, the device I is arranged so that it admits the lifting of the inner roll B V a distance corresponding to the thickness of a supporting plate F. In order that the bearing body D with the supporting plates F will bear against the mandrel head E, pressure fluid is applied to the top of the piston H after each supporting plate F has been pushed in. In this instance the pressure need be maintained only until the inner rolls B have gripped the material to be rolled. A device is further provided, by which the movement of the pressure springs G is limited. This device consists of a simple plate M placed between pressure springs G and supporting plates F. To prevent the plate M from moving up against the lid of the storage chamber when the last supporting plate has been pushed in under the bearing body D and to ensure that a gap equal to the thickness of a supporting plate F remains free between plate M and lid Q, stop pins S or similar devices are provided on the walls of the chamber X which are engaged by and limit the movement of the plate M. The plate M has a key a corresponding to the groove of the adjacent supporting plate F, and in its highest position it is flush with the bottom edge of the slot b of the mandrel head E on to which edge the supporting plate is pushed. This is necessary,-in order that in the following operation the supporting plates F can be pulled back freely from the gap between mandrel head E and bearing body D, if the roll B is not to be further advanced in radial direction to the material to be rolled but to be moved away from the same. Fig. 3a is similar to Fig. 3 but shows the elements in their position after one supporting plate F has been inserted between bearing body D and mandrel head E.

From Fig. 4 it is evident that the supporting plates F have slots F so that the arms of the member I do not hinder the pushing of F between E andD.

As shown in Fig. 6 supporting plates F can be used which have, at the points at which the device L engages, indentations in which clamping springs N are located. In this instance the device L is pushed forward by the press piston K, the end of device L engages into the indentation in the supporting plate F, the clamping springs snap in and the supporting plate F can be pulled back with the aid of device L into the chamber X which is provided for accommodating the supporting plates F in the mandrel head E. In this instance a spreading pin 0 or a similar element must become eifective at the termination of this pulling back and open the clamping springs N so that device L can be completely pulled back. In order that the space in the top Fig. 7 shows how this takes place. If the inner roll has to be moved away from the material to he rolled by removing the supporting plates F,

the device I is rigidly connected with plate M. The device I must further be connected with the extensionof the shaft of the inner roll D so that device I can follow the movement of the piston H, when this piston moves into its cylinder.-

Fig. 8 shows another manner of actuating the fork L, which pushes or pulls the supporting plates F. Such an arrangement is advisable when it is possible that the exposed press cylinders K, as shown in Fig.3, might be damaged dur-- ing manipulation of the material to be rolled. A lever P which is destined, as shown in Fig. 8, to actuate the device L cannot be compared with the adiusting devices for the inner roll mentioned above and comprising a leverage. Whereas in this leverage for adjusting the inner rolls the rolls have to be held in their position during the rolling by the leverage itself, the leverage shown in Fig. 8 serves merely for pushing supporting plates under the bearings or pulling them out of the bearings, whereas the working pressure during the rolling is not transmitted upon this-leverage.

Iclaim: 1. In a rolling mill for rolling pipes, a mandrel head, bearing bodies movable on said head, a

roll mounted in the bearing bodies, means for moving said bearing bodies stepwise in opposite directions radially of said head, a plurality of supfor removing the inserted plates in advance of ea'ch inward movement of the bearing bodies.

2. A device as claimed in claim 1 wherein the bearing bodies and plates have dove-tailed keys and grooves which mutually coact to cause the plates to follow the movement of the bearing bodies.

A 3. A device as claimed in claim 1, having means tending to move the supporting plates into position for insertion between said bearing bodies and said head, and means for limiting the movement of said plates.

4. A device as claimed in claim 1 having means for limiting each outward stepwise movement of the bearing bodies'to an extent corresponding with the thickness of the supporting plates.

5. A device as claimed in .claim 1 characterized by the provision of chamber in said mandrel head for successively receiving the supporting plates removed from between said bearing'bodies and said head, and interengaging means on said plates imparting movement or one plate to the other within said chamber.

6. A device as claimed in claim 1 characterized by the provision of a chamber in said mandrel head for receiving said supporting plates one upon the other, means normally tending to move supporting plates into position for insertion between said bearing bodies and said head, said plate inserting and removing means beingpositioned to cooperate with the uppermost supporting plate.

'7. A device as claimed in claim 1 characterized by'the provision of a chamber for accommodating the supporting plates one upon the other, the plate inserting and removing means being arranged to coact with the uppermost plate in said chamber, and dove tail key and grooves on the bearing bodies and plates mutually coacting to cause the plates to follow the movement of the bearing bodies in one direction.

8. A device as claimed in claim 1 wherein said plate inserting and removing means includes a push pull member and a releasable coupling means between said push pull member and said plates for effecting removal thereof.

9. A device as claimed in claim 1 characterized in that said means for moving the bearingbodies and the 'means for inserting and removing the supporting plates are fluid operated.

10. A device as claimed in claim 1 characterized in that the means. for moving the bearing bodies and the means for inserting and removing the supporting plates are independently operable by fluid pressure;

' MARTIN .ROECKNER. 

